Metallic audion.



L. `mi FOREST;

METALLIC A UDIO'N. APPLICATLON `FILED- FEE. 2l.` 191:1.'

Patented June 26, 1917.

7n 4 n n n n M/ AWWA UNITED STATES PATENT OFFICE.

LEE DE FOREST, OF NEW YORK, N Y., ASSIGNOR T DE FOREST RADIO TELEPHONE AND TELEGRAPH COMPANY, OF NEW YORK,` N. Y., A CORPORATION OF DELAWARE.

METALLIC AUDION.

Patented June 26, 1917.

Application filed February 21, 1917. Serial No. 150,027.

To all whom it may concern.: Be it known that I, Lne on Fonns'r, a citizen of the United States, residing at New York, in the county and State of New York, have made a. certain new and useful Invention in Metallic Audions, of which the following is a specification.

This invention relates to audions.

The object of the invention is to provide an audion which is simple in structure and which will lallow rough handling without the danger of breakage in shipment and in use.

A further object of the invention is to provide an audion with a metal shell which shell will form one electrode of the devlce.

Further objects of the invention will appear more fully hereinafter.

The invention consists substantially in thev construction, combination, location and relative arrangement of parts, all as will be lnore fully hereinafter set forth, as shown in the accompanying drawing, and linally pointed out in the appended claims.

Referring to the drawing Figure 1 is a view in vertical section of an audion embodying my invention.

Fig. 2 is a similar view of a modied structure embodying my invention.

The same part is designated by the same reference numeral wherever it occurs throughout the several views.

The commercial vform of audion used as an oscillation generator and known as an oscillion now on the market comprises an evacuated glass vessel of various shapes, with the electrodes of the audion sealed there through in the usual way. These glass audions are necessarily fragile, and in consequence require great care in handling and shipping the same.

It is among the special purposes of my present invention -to provide an audion which can stand a lot of abuse in handling and shipping the same without the danger of breakage. f

In accordance with my invention I provide a metal flask 1 open at one end and provided with a restricted neck 2 at the other end.` In the restricted neck portion of the ask I place a thin ring 'of steel, tungsten or other metal, indicated at 3, and weld this ring to the flask as indicated. A yoke 5 is then inserted in the flask through the bottom 4: thereof, which yoke has wound there about the grid wire or electrode (i. '.lhe yoke also forms a support for the filament electrode 7. It will be. seen that with this arrangement the grid electrode surrounds the filament but is insulated therefrom. The yoke 5 may be of any suitable material, but I have found that a solid glass yoke is satisfactory for the purpose. The leadsv of the filament pass through the yoke 5 out of the stopper 8, as shown at 9 and 10. The stopper 8 is preferably of glass and is forced into the neck formed by the thin metal plate or ring 3 while both the ring and stopper are hot to thereby secure an air tight joint. The yoke 5 is thus supported by the stopper 8. The grid wire 6 is sealed through the stopper as shown at 11. A metal bottom 12 for the ask is then welded to the open end 4 thereof, and the completely inclosed receptacle thus formed is connected to a vacuum pump and is thereby exhausted of air through the tip 13 of the stopper 8, which is thereafter sealed as is well known in the glass blowing art.

It will be seen that I have provided an exceedingly simple and strong structure of audion wherein the containing vessel forms one electrode of the audion as in this instance-the flask 1 is the wing or plate electrode and is provided with a terminal 14. The problem of keeping the audion cool when in use is exceedingly simple in this type of audion in that the entire ask up to the stopper may be submerged in a cooling iuid.

/In Fig. 2 I show a modified structure of metal audion wherein I dispense with the .bottom 12, and the ring 3 and form the flask in one piece. In this arrangement, the open end of the liask 1 is narrowed or tapered as shown at 15 into a thin metal ring. The

'glass stopper 8 carrying the filament and wish it to be understood that many arrangements and modications will readily occur to those skilled in the art without departing from the spirit of my invention or the scope thereof as defined in the claims. Therefore, what I claim as new and useful and of my own invention and desire to secure by Letters Patent is 1. The method of constructing a metal audion which consists in forcing a glass stopper under heat and carrying two electrodes, in a thin metal ring under heat and carried by a metal flask and finally exhausting the air from said flask.

2. The method of constructing a` metal audion which consists of first welding a thin metal ring to one end `of a metal flask, inserting through the other end of said .flask an electrode bearing stopper, forcing said stopper into said thin ring while both said ring and said stopper are heated, welding an inclosing cap to the other end of the flask, and finally evacuating said flask of air through said stopper. f

3. A metal audion comprising a metal receptacle open at one end, and provided with a neck portion of less thickness than the body of the receptacle, a glass stopper sealed to said thin neck portion and supporting two electrodes of the audion, the leads of said electrodes passing through said glass stopper.

' 4. An audion comprising an evacuated metal shell provided with a glass stopper :forced while hot in the neck of said shell,

metal shell provided with a glass stopper forced while hot in the neck of said shell, said stopper supporting two electrodes of said audion, said shell forming the third electrode of said audion.

6. An audion comprising an evacuated metal shell provided with a relatively thin neck, a glass stopper 'sealed to said neck, said glass stopper supporting two electrodes of said audion.

7, An audion comprising an evacuated metal shell provided with a restricted neck portion, a thin metal ring welded to said shell within said restricted neck portion, and a stopper sealed to said metal ring, said stopper supporting two electrodes of the audion. v

8. An audion comprising an evacuated metal shell provided with a restricted neck portion, a thin metal ring welded to said shell within said restricted .neck portion, and a stopper sealed to said metal ring, said stopper supporting two electrodes of the audion, and said shell forming the third electrode of said audion.

In testimony whereof I have hereunto set my hand on this 15th day of February LEE DE FOREST. 

